Automatic power transmission



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AUTOMATIC POWER TRANSMISSlON. APPLICATION FILED OCT. 2's. 191s.

1,31 1,236. Patentd July 29, 1919.

- W/TNESSES l/VVEN Tole.

- TnpsTATEs-PATEN erosion. v

' JOHN W. KITTREDGE, 0F AKRON, OHIO.

- AUTOMATIC POWER TRANSMISSION,

Specification of Letters Patent. Pate t d J l 29 jApplicationjiled ember 191s; SeriarNo. 128,244.

. To all whom it may-concern." Be it known th'atI, J on W. Krrrlmnen, a citizen of the United States, residingat Akron, in the county of Summit and State of Ohio, have invel'ited a newand useful The objects of my 1mpro'vements are:-

1st. To provide a power transmission inwh1ch the driving and driven members are connected by gears and other positive inter.-

locking parts, securing positive action and absolute safety.

-2nd. To provide a transmission in which different loads or torques upon the driven member automatically put different trains of mechanism into operation, giving different speeds of the driven member from a uniform speed of the driving member, the

greater torque on .the driven member pro-- ducing in it a. less speed, and the less torque on the said driven member producing in it a greater speed.-

- I attain'theseobjects by the mechanism herein described which I have shown as applied to a chain block or chain-hoist, although it is applicable to many other classes of machinery. The brake and chain guide essential to a chain holstare omitted'from the drawings as not pertinent to this ,invent-ion. v

Figure l is a longitudinal section on line ferent edges or faces of that part by that numeral with letters, as 5*, 5 5 etc. 'Parts fastened together and having the same m0- A tion are cross-hatched alike, even though they may be separate pieces of metal. A

' given piece carries the same number throughout the several views.

,The block is hung from an overhead support by the hook 1, which is attached to the side-supports 2 and 3 by the swivel bar 4. A

sprocket wheel 5 runs in the supports 2 and 3 and carries a lifting chain-6. A hand chain 7 aotuates a sprocket wheel 8, which, in turn, actuates the shaft 9, which, for my purpose, is the driving shaft, It actuates a set of planetary gears as follows :A central-pinengagement with the ratchet 13".

'with 'two intermediate pinions 11, and they mesh with the annular gear '12, which is made fast to the side support 2, and is therefore, stationary. The pinions 1.1' are held in a carrier 13. As the shaft 9 andthe pinion 10 turn, the pinions 11 turn on their own axes and also-turn with the carrier 13 about the shaft 9.; The shaft 9 and the carrier 13 always turn in the same direction, but the shaft turns much faster than the carrier. By means new to be described, the-sprocket wheel 5, the driven member, may be locked eitherto the shaft 9 orto the carrier 13, thus giving it two different speeds. from a uniformspeed of the driving shaft 9.

13". The piece '11 fits loosely on'the shaft 9 and may rock backand forth on it through a partial revolution. Two springs 15 attach to the piece 1'4, and bear, at their free ends. on two projecting lugs 5 which are rigid with the sprocket wheel 5. The piece 14 has two projecting lugs 11", which carry two pawls 16.- Each pawl is slotted and engages therein a lug 5", which, also, is rigid with the sprocket. lVith a small torque on the sprocket 5, 'the springs 15 throw the lugs 5 away from the piece 14, to the position shown in Figs. 1 and 2. The lugs 5 simultaneously throw the hooks 16 or the pawls 16 intoengagement with the ratchet 10, as shown. And'as the shaft 9 is rotated in the direction indicated by the arrows, with small torque on the sprocket wheel 5, the springs 15 move the lugs 5 and the sprocket 5 with the same speed as the shaft 9, and maintain the. hooks 16 in engagement with the ratchet 10 a \Vhen, however, a load is applied to the lifting chain 6, and a greater torque to the sprocket 5, opposite to the indicated direction of rotation, the lugs 5 compress the springs 15 down against the piece 14. At the same time, the lugs 5 throw the pawls 16 on the fulcrums 14 and throw them out of engagement with the ratchet 10 and into The sprocket 5 then takes the slow speed of the carrier 13. The pawl 16 is solarge that it must be in engagement with one ratchet or the other at all times, and it must remain in engagement with one ratchet until it finds the position where it can shift to the other. This makes it impossible for the load to run *back while a; shaft}? 'turns'iin'the direction indica,ted'.. .When the pawls 16 engage" the ratchet 13, their: forward ends engage against the lugs 5 which are ri id with the It will 'be noted that the. shifting mechanism is-entirely inclosed and is protected from the operator, as well as'from dirt and accidental-injury; that it is actuated only bythe1-tens1on' on the lifting. chain; that so long} as" there is a heavy tension on that chain, the'load must necessarily run on slow speed; that so long as there is a light tension .on that chain, it-must necessaril Y run on be. run eitherup or down oneither fast or slow speed, depending on its tension: The

7 block may be caused to shift speed at any desired loadand at that load only,'by giving to ,the' springs 15 a 'corresponding stiffness. WVith excessive frictionresulting from wear or other'cause, .thesprings 15 may fail to throw in-the fast'motion. The heavy pull of the load cannot fail .to throw in the slow motion .until the mechanism A is injured beyond the possibility of use. If it fai1s to it must fail on the side ofsafety. By; duplicating this. mechanism, a third speed may be introduced, the block adjusting itself automatically to three different 'speeds corresponding to three different loads; and by repeating this mechanism, the

number of speeds may be multiplied indefinitely;

Having thus described my invention, I

claim as new and desire to secure by Letters 1. A transmission mechanism comprising a driving and a driven member, a plurality of means for transmittingpower comprising interlocking members and adapted to transmit power through any one of said means from the driving to the drivenmember, shifting mechanism whereby a change of load on the driven member shifts the trans-- mission from one transmitting means to another, and interlock ng members adapted to 'holdone or'another of the transmittinghaving a different speed ratio from the others, a shifting mechanism" operated. by the driven member for shifting from one transmitting'mea-ns to another controlled'by varying torques on the driven member, and

interlocking members adapted to steadily and continuously hold one or another of the transmitting means in operation exceptas a change of torque on the driven member ,shifts the transmission'to a different transhigh speed, and that the lifting-c ainmay ratchet connections between the drive shaft and the driven wheel, and means whereby a change of torque on the driven wheel holds said mechanism alternately in locked and re.-

leased positions.

4. Atransmisslon mechanism comprisingv a drive shaft,'a driven wheel, a pinion on the said drive shaft, a set of planetary gears in mesh with the said pinion, a carrier for the said planetary gears, a ratchetrigidly connected to the said drive shaft, :1 second ratchet rigidly connected to the said carrier of the planetary'gears, pawls, means on the said driven wheel adapted to engage the said pawls, springs adapted to throw the said pawls out of engagement with the ratchet on the carrier and into engagement with the ratchet on thedrive shaft, and means whereby the torque on the driven wheel controls the operation of the springs. In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses, this 23rd day of October, 1916.

I JOHN T. KITTREDGE. Witnesses:. Y

EDWIN J. WRIGHT, CHAS. A. RosK sK 

